<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>打印三角形</title>
<script type="text/javascript">
document.write("<center>");
var row=parseInt(prompt("请输入打印的行数",""));
for(var i=0;i<row;i++)
{
	for(var j=0;j<=i;j++)
	{
		document.write(" * ");
	}
	document.write("<br/>");
}
document.write("</center>");
</script>
</head>

<body>
</body>
</html>
